The calculation of the basic and diluted earnings per share is based on the following data:
| 2018
£m | 2017
£m |
| Earnings | | |
| Earnings for the purpose of basic earnings per share being net profit attributable to equity holders of the parent | 103.2 | 97.1 |
| Number | Number |
| Number of shares | | |
| Weighted average number of ordinary shares for the purpose of basic earnings per share | 190,289,981 | 190,250,855 |
| Effect of dilutive potential ordinary shares: | | |
| Share options | – | – |
| Weighted average number of ordinary shares for the purpose of diluted earnings per share | 190,289,981 | 190,250,855 |
| Pence | Pence |
| Earnings per share: | | |
| Basic | 54.2 | 51.0 |
| Diluted | 54.2 | 51.0 |
| £m | £m |
| Headline earnings | | |
| Net profit attributable to equity holders of the parent | 103.2 | 97.1 |
| Add back: | | |
| Amortisation of acquired intangible fixed assets (net of tax) | 2.8 | 2.9 |
| Acquisition costs (net of tax) | 0.5 | – |
| Less: | | |
| Impact of US Tax Cuts and Jobs Act treated as an exceptional item | – | (6.4) |
| Headline earnings | 106.5 | 93.6 |
| Pence | Pence |
| Headline earnings per share: | | |
| Basic | 55.9 | 49.2 |
| Diluted | 55.9 | 49.2 |